Full Opening Safety valve (FOSV)


  1. Available with a wide variety of sizes and end connections
  2. Operating wrench and thread protectors included
  3. Major repair kits available for every valve
  4. Comes with certified test report
  5. Identifiable open and close markings
  6. Can be H2S corrosion resistant as per NACE MR0175


Full Opening Safety valve (FOSv) is a ball-type safety valve used to stop flow through the drill string when the drill string is being withdrawn from the well. FOSv is a dual body full-opening safety valve, that does not interfere with the running of tools such as core barrels or survey instruments. It is designed to be stabbed into the top joint of drill pipe or tubing string at the rig floor and closed quickly in case a well kicks.

The ball-type design permits the valve to be compact, easy to handle, and have great strength. The standard test pressure is 10,000 psi, but higher-pressure ratings are available.


Type Exradius OD Inch (mm) Inradius ID Inch (mm) Connecting thread API working pressure MPa
FOSV79 3-1/9 (79) 4/5 (20) 2-7/8HT PAC 35-70
FOSV89 3-1/2 (89) 1-3/16 (30) NC26
FOSV111 4-3/8 (111) 1-37/64 (40) NC31
FOSV121 4-3/4 (121) 1-31/32 (50) NC38
FOSV127 5 (127)
FOSV133 5-1/4 (133) 2-11/25 (62) NC40
FOSV159 6-1/4 (159) 2-4/5 (71) NC46
FOSV165 6-1/2 (165) 2-13/16 (71.4) NC50
FOSV168 6-5/8 (168)
FOSV190 7-1/2 (190) 3 (76.2) 5-1/2FH



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